76 3I0SQUIT0ES 



life of the wri^-g-lers may be almost indefinitely pro- 

 long-ed. I have watched them for twenty days, during 

 which time they did not reach full g-rowth. The short- 

 ness of the minimum generation, however, is ver}' signifi- 

 cant and accounts for the fact that swarms of mosquitoes 

 develop upon occasion in surface pools of rain-water, 

 which may dry up entirely in the course of two weeks or 

 less, or in a chance bucket of water left undisturbed for 

 that length of time. 



Dr. John B. Smith has reared the species, as elsewhere 

 stated, from larvae found in January frozen in ice. In 

 studying the larv;ie after they had been thawed out he 

 found that they remained under the water for a long 

 time, certainly fifteen minutes, and probably much 

 longer. These observations thus difier radically from 

 those which I made in summer, and show that these larv;© 

 must be studied still more before we know all that may 

 be found out about them. 



This species, Cuhx pxnr/efts, is said by Dr. H. A. Yea- 

 zie, of N(nv Orleans, to breed most extensively in the 

 gutters in that city. They are found in gutters in whicli 

 the water runs slowly, l)ut more plentifully' in those where 

 there is no current. In gutters that receive the refuse of 

 the gas works, tar factories, soap works, and oil establish- 

 ments, there are no larvfe. They live in gutters contain- 

 ing Mississippi River water, but do not i>rosper. Dr. 

 Yeazie thinks the fine sedinuMit in the ^Mississippi water 

 blocks their br(\atliinq' tub >s, since they fionrish well in 

 this water after it hns \)vo]\ filt('r(Ml. 



Reverting once more to the distribution of thedifterent 



